Two microcontrollers released by STMicroelectronics offer low power performance for budget conscious consumer, industrial and medical applications.

The STM32L4 microcontrollers, the STM32L412 and STM32L422, combine economical 64kbyte or 128kbyte flash density with ST’s FlexPowerControl (FPC), and the 80MHz Arm Cortex-M4 core. According to ST, they set best-in-class EEMBC benchmarks for efficiency and performance, namely 273 CoreMark for fast execution in devices like smart sensors or consumer wearables, 167 ULPMark-PP (Peripheral Profile) and 447 ULPMark-CP (Core Profile) for energy management.

The multiple reduced-power modes can maximise battery life, while analogue peripherals including two ADCs perform simultaneous acquisition and a comparator integrate more of the signal chain on-chip, for sensing or heart-rate monitoring.

The STM32L412 and STM32L422 are available in additional package options including 5.0 x 5.0mm LQFP32 or 2.58 x 3.07mm WLCSP36, to save component count and board space.

A choice of temperature grades, specified from -40 to +85 or +125 degrees C, withstand tough conditions in industrial or medical applications. Flash error correction (ECC) and parity-checking hardware for on-chip SRAM contribute to system safety. A Quad-SPI allows high-performance off-chip memory extension, while peripheral cater for control and connectivity.

The microcontrollers can be use in smart meters, where their high dynamic efficiency draws as little as 28 microA/MHz. The integrated ADCs, anti-tamper inputs on battery and backup-power domains, a true random-number generator (TRNG), and support for AES-256 encryption in the crypto-enhanced STM32L422 ensure high accuracy and strong protection, says ST.

Developers can access the STM32 ecosystem, for example the STM32CubeL4 software package and the STM32CubeMX initialisation code generator and power consumption calculator to start work using the STM32L412 and STM32L422 immediately.

Two new Nucleo boards, the Nucelo-L412RB-P containing a 64-pin STM32L412 with step-down converter, and the Nucelo-L412KB with a 32-pin STM32L412 have also been introduced by ST.

The STM32L412 and STM32L422 are in production now, with up to 128kbyte flash and 32-pin to 64-pin packages.